Telephone systems are known which provide a common interface between a plurality of users and a public telephone network. These systems have been referred to as PBX systems. A typical PBX system includes a central box with line cards providing connections to assigned lines of a public telephone network. The central box is connected by wires such as twisted pair wires to individual telephone units. The connection from the central box to the telephone units may be by way of analogue or digital signals. More recently, digital signals are sent by the central unit to the phone units. The digital signals include voice data as well as control and messaging data. The units typically include a simple handset as well as a speaker for paging, intercom type communications and speaker phone applications. Typically the base unit also includes a microphone. The handset is a typical handset providing a speaker and a microphone.
Telephone systems using distributed networks, such as local area networks (LANs) are also generally known. With these systems, a distributed network is provided, such as CSMA/CD (see IEEE 802.3) generally known as Ethernet. A telephone network system is provided with a central box having line cards connected to the distributed network as well as network devices connected to the network. The network devices include network telephones with, for example, a base unit with a speaker and a microphone and a handset (with a speaker and a microphone). Data packets are sent over the network between network devices. A network control processor or network call processor (NCP) may be used to monitor and control the access to the public telephone network. Features specific to the user may be established with the NCP.
Digital PBX systems are known which include a display associated with the PBX telephone unit and which have keys allowing entry of data into the system via the PBX telephone unit. This allows for the storage of frequently called numbers (speed dial numbers) and other user specific information (name of the user associated with the PBX telephone unit etc.). Such systems are notoriously difficult to program and reconfigure for different users.